So, in RHOSP13 fake_pxe is being deprecated to change in RHOSP14 for manual-management, the problem is that is just in between the migration, so there is not a clean way to use fake_pxe in RHOSP13.
Other change is in the installation of undercloud, the option enabled_drivers is now DEPRECATED an changed by enabled_hardware_types.
What now, in order to being able to use fake_pxe as a pm_type first install the undercloud without the options enabled_drivers, only use enabled_hardware_types and add at the end manual-management, like this: